1. Field of Invention
The present invention relates to an apparatus for acoustically improving an environment and to a related method.
2. Description of Related Art
Noise has been recognized as a major problem in industrial, office, and domestic environments for many years now. Advances in materials technology have provided some solutions. However, the solutions have all addressed the problem in the same way, namely: the sound environment has been improved by decreasing noise levels in a controlled space. This relatively inflexible approach has been regarded as a major design guideline in the design of spaces as far as noise abatement is concerned.
In particular, U.S. Pat. No. 5,355,418 describes a hearing aid for wearing as an ear piece, which is designed to monitor ambient noise for frequency components above a pre-selected threshold level and to filter out such frequencies utilizing an adaptive digital filter.
U.S. Pat. No. 5,105,377 concerns an active noise cancellation system arranged to sense residual noise and to generate an electronic waveform for activating an acoustic activator to produce an acoustic cancellation signal. In this system, an adaptive filter is employed whose filtering characteristics are adjusted on the basis of the residual noise and of the estimated effects of the cancellation signal as well as the system impulse response. The adaptive filter thus filters the estimated noise to generate the cancellation signal.
U.S. Pat. No. 5,315,661 concerns an arrangement for sound reduction employing a passive sound absorbing panel, a sensor, and an activator for actively attenuating sound signals received by the sensor.